Tuesday, May 27, 2014

New paper finds Ross Sea ice in Antarctica has increased 5% since 1993

A new paper published in Geophysical Research Letters reconstructs sea-ice area in the Ross Sea, Antarctica from a 130 year coastal ice-core record. The authors find the "data show prevailing stable SIA from the 1880s until the 1950s, a 2–5% reduction from the mid-1950s to the early-1990s, and a 5% increase after 1993."

Thus, the overall trend in the Ross Sea, Antarctica over the past 130 years would be stable to increasing.

We present the first proxy record of sea-ice area (SIA) in the Ross Sea, Antarctica, from a 130 year coastal ice-core record. High-resolution deuterium excess data show prevailing stable SIA from the 1880s until the 1950s, a 2–5% reduction from the mid-1950s to the early-1990s, and a 5% increase after 1993. Additional support for this reconstruction is derived from ice-core methanesulphonic acid concentrations and whaling records. While SIA has continued to decline around much of the West Antarctic coastline since the 1950s, concurrent with increasing air and ocean temperatures, the underlying trend is masked in the Ross Sea by a switch to positive SIA anomalies since the early-1990s. This increase is associated with a strengthening of southerly winds and the enhanced northward advection of sea ice.